如何使用SQL查询显示像父子一样的层次结构行
我在我的应用程序中使用博客评论，我在一个表中插入每个评论行，所以如果他们中的任何一个回复了点击commentid我在新行中插入replyid的特定评论
以下是屏幕截图：
在这里，您可以看到commentid 24和26正在replycommentid 23。
我需要一个查询在23之后显示24和26.因为23是24和26的父。
以下是表格布局和示例数据的设置脚本：
USE [myDB]
GO
/****** Object: Table [dbo].[Blog_CommentDetails] Script Date: 11/12/2016 6:36:04 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
CREATE TABLE [dbo].[Blog_CommentDetails](
[CommentID] [int] IDENTITY(1,1) NOT NULL,
[CommentUserName] [nvarchar](200) NOT NULL,
[CommentText] [nvarchar](max) NULL,
[CommentApprovedByUserID] [int] NULL,
[CommentPostDocumentID] [int] NOT NULL,
[CommentDate] [datetime] NULL DEFAULT (getdate()),
[HtmlComment] [nvarchar](max) NULL,
[CommentIsSpam] [bit] NULL CONSTRAINT [DEFAULT_Blog_MainComment_CommentIsSpam] DEFAULT ((0)),
[CommentIsApproved] [bit] NULL CONSTRAINT [DEFAULT_Blog_MainComment_CommentIsApproved] DEFAULT ((0)),
[CommentEmail] [nvarchar](250) NULL,
[CommentInfo] [nvarchar](max) NULL,
[ReplyCommentID] [int] NULL
) ON [PRIMARY] TEXTIMAGE_ON [PRIMARY]
GO
SET IDENTITY_INSERT [dbo].[Blog_CommentDetails] ON
GO
INSERT [dbo].[Blog_CommentDetails] ([CommentID], [CommentUserName], [CommentText], [CommentApprovedByUserID], [CommentPostDocumentID], [CommentDate], [HtmlComment], [CommentIsSpam], [CommentIsApproved], [CommentEmail], [CommentInfo], [ReplyCommentID]) VALUES (22, N'Vikash', N'This is main comment', NULL, 1, CAST(N'2016-11-12 17:36:25.637' AS DateTime), N'<div class="main-comment-section"><div class="row"><div class="col-xs-12"><div class="post-comment-section"><p id="pCommentorName"><span id="sCommentorName" class="blogcommentname">Vikash</span><span id="sBlogPostedDate">Nov12,2016 5:35PM</span></p><p class="comment-detail" id="pBlogCommentDetails">This is main comment</p><div class="comment-reply"><ul><li><img src="assets/svg/components/blog-detail/icon_reply.svg" alt="Reply comment icon"><a class="joinus-link" id="btnComment" href="#" target="_self">::blogdetailsReply</a></li></ul></div></div></div></div></div>', 0, 1, N'vikash.kr@sonata-software.com', NULL, NULL)
GO
INSERT [dbo].[Blog_CommentDetails] ([CommentID], [CommentUserName], [CommentText], [CommentApprovedByUserID], [CommentPostDocumentID], [CommentDate], [HtmlComment], [CommentIsSpam], [CommentIsApproved], [CommentEmail], [CommentInfo], [ReplyCommentID]) VALUES (23, N'Megha k', N'This is reply comment', NULL, 1, CAST(N'2016-11-12 17:39:04.250' AS DateTime), N'<div class="reply-comment-section"><div class="row"><div class="col-xs-12"><div class="post-comment-section"><p id="pBlogReplyCommentorName"><span id="sReplyCommentorName" class="blogcommentname">Megha k</span><span id="sBlogReplyCommentDate">Nov12,2016 5:38PM</span></p><p class="comment-detail" id="pBlogReplyCommentDetails">This is reply comment</p><div class="comment-reply"><ul><li><img class="contributors-list" src="assets/svg/components/blog-detail/icon_reply.svg" alt="Reply comment icon"><a class="joinus-link" id="btnCommentReply" href="#" target="_self">::blogdetailsReply</a></li></ul></div></div></div></div></div>', 0, 1, N'megha.k@sonata-software.com', NULL, NULL)
GO
INSERT [dbo].[Blog_CommentDetails] ([CommentID], [CommentUserName], [CommentText], [CommentApprovedByUserID], [CommentPostDocumentID], [CommentDate], [HtmlComment], [CommentIsSpam], [CommentIsApproved], [CommentEmail], [CommentInfo], [ReplyCommentID]) VALUES (24, N'Siddappa H', N'This is reply text.', NULL, 1, CAST(N'2016-11-12 17:39:58.847' AS DateTime), N'<div class="main-comment-section"><div class="row"><div class="col-xs-12"><div class="post-comment-section"><p id="pCommentorName"><span id="sCommentorName" class="blogcommentname">Siddappa H</span><span id="sBlogPostedDate">Nov12,2016 5:39PM</span></p><p class="comment-detail" id="pBlogCommentDetails">This is reply text.</p><div class="comment-reply"><ul><li><img src="assets/svg/components/blog-detail/icon_reply.svg" alt="Reply comment icon"><a class="joinus-link" id="btnComment" href="#" target="_self">::blogdetailsReply</a></li></ul></div></div></div></div></div>', 0, 1, N'siddappa.h@sonata-software.com', NULL, 23)
GO
INSERT [dbo].[Blog_CommentDetails] ([CommentID], [CommentUserName], [CommentText], [CommentApprovedByUserID], [CommentPostDocumentID], [CommentDate], [HtmlComment], [CommentIsSpam], [CommentIsApproved], [CommentEmail], [CommentInfo], [ReplyCommentID]) VALUES (25, N'Suresh P', N'This is reply comment', NULL, 1, CAST(N'2016-11-12 17:40:44.470' AS DateTime), N'<div class="reply-comment-section"><div class="row"><div class="col-xs-12"><div class="post-comment-section"><p id="pBlogReplyCommentorName"><span id="sReplyCommentorName" class="blogcommentname">Suresh P</span><span id="sBlogReplyCommentDate">Nov12,2016 5:40PM</span></p><p class="comment-detail" id="pBlogReplyCommentDetails">This is reply comment</p><div class="comment-reply"><ul><li><img class="contributors-list" src="assets/svg/components/blog-detail/icon_reply.svg" alt="Reply comment icon"><a class="joinus-link" id="btnCommentReply" href="#" target="_self">::blogdetailsReply</a></li></ul></div></div></div></div></div>', 0, 1, N'suresh.p@sonata-software.com', NULL, NULL)
GO
INSERT [dbo].[Blog_CommentDetails] ([CommentID], [CommentUserName], [CommentText], [CommentApprovedByUserID], [CommentPostDocumentID], [CommentDate], [HtmlComment], [CommentIsSpam], [CommentIsApproved], [CommentEmail], [CommentInfo], [ReplyCommentID]) VALUES (26, N'Vikash', N'This is reply text', NULL, 1, CAST(N'2016-11-12 17:41:44.673' AS DateTime), N'<div class="reply-comment-section"><div class="row"><div class="col-xs-12"><div class="post-comment-section"><p id="pBlogReplyCommentorName"><span id="sReplyCommentorName" class="blogcommentname">Vikash</span><span id="sBlogReplyCommentDate">Nov12,2016 5:40PM</span></p><p class="comment-detail" id="pBlogReplyCommentDetails">This is reply text</p><div class="comment-reply"><ul><li><img class="contributors-list" src="assets/svg/components/blog-detail/icon_reply.svg" alt="Reply comment icon"><a class="joinus-link" id="btnCommentReply" href="#" target="_self">::blogdetailsReply</a></li></ul></div></div></div></div></div>', 0, 1, N'vikash.kr@sonata-software.com', NULL, 23)
GO
SET IDENTITY_INSERT [dbo].[Blog_CommentDetails] OFF
GO
欢迎所有建议！
我在下面添加了三个插入查询：
Valex，请在表中插入此查询，即“INSERT [dbo]。[Blog_CommentDetails]（[CommentID]，[CommentUserName]，[CommentText]，[CommentApprovedByUserID]，[CommentPostDocumentID]，[CommentDate]，[HtmlComment] ]，[CommentIsSpam]，[CommentIsApproved]，[CommentEmail]，[CommentInfo]，[ReplyCommentID]，[IsRejected]）VALUES（58，N'Vicky'，N'Test'，0,1，CAST（N'2016-） 12-02 11：51：07.270'AS DateTime），N'VickyDec2,2016 11:47 AM
测试
- 回复
这是评论测试
- 回复
这是rakesh测试
- 回复
我正在编辑我的问题。
请检查下面的屏幕截图：
我使用了以下查询：
WITH CTE AS ( SELECT CommentID ,
CommentPostDocumentID ,
CommentIsApproved,
CommentDate ,
ReplyCommentID ,
CommentUserName,
CommentID AS ThreadID ,
CAST( CommentID AS VARCHAR( MAX ) ) AS PathStr
FROM Blog_CommentDetails AS T WITH(NOLOCK)
WHERE ReplyCommentID IS NULL
UNION ALL
SELECT T.CommentID ,
t.CommentPostDocumentID ,
t.CommentIsApproved,
T.CommentDate ,
T.ReplyCommentID ,
T.CommentUserName,
CTE.ThreadID ,
PathStr + '-'+ CAST( T.ReplyCommentID AS VARCHAR( MAX ) ) AS PathStr
FROM Blog_CommentDetails AS T WITH(NOLOCK)
JOIN CTE
ON T.ReplyCommentID = CTE.CommentID
WHERE T.ReplyCommentID IS NOT NULL )
SELECT *
FROM CTE
WHERE CommentPostDocumentID = 18 AND CommentIsApproved=1
ORDER BY ThreadID ,
PathStr ,
CommentDate DESC
以下是显示评论的图片：
以下是预期的结构：
- Vikash评论
- Sid回复vikash评论。
- Megha对vikash发表了评论，因此在父母Vikash的指导下，比起Sid更为出色。
- QE回复了Megha的评论，所以他应该比Sid更好，但它在最后一排。
4 个答案:
答案 0 :(得分：3)
如果您想要完整的层次结构或甚至是其中的一部分，请使用正确的序列
编辑 - 删除了2008年的Concat（）
Declare @Top int = 23 --null --<< Sets top of Hier Try 23
Declare @Nest varchar(25) ='|-----' --<< Optional: Added for readability
;with cteP as (
Select Seq = cast(1000+Row_Number() over (Order by CommentID) as varchar(500))
,CommentID
,ReplyCommentID
,Lvl=1
From [dbo].[Blog_CommentDetails]
Where IsNull(@Top,-1) = case when @Top is null then isnull(ReplyCommentID,-1) else CommentID end
Union All
Select Seq = cast(p.Seq+'.'+cast(1000+Row_Number() over (Order by r.CommentID) as varchar(25)) as varchar(500))
,r.CommentID
,r.ReplyCommentID
,p.Lvl+1
From [dbo].[Blog_CommentDetails] r
Join cteP p on r.ReplyCommentID = p.CommentID)
,cteR1 as (Select *,R1=Row_Number() over (Order By Seq) From cteP)
,cteR2 as (Select A.Seq,A.CommentID,R2=Max(B.R1) From cteR1 A Join cteR1 B on (B.Seq like A.Seq+'%') Group By A.Seq,A.CommentID )
Select A.R1
,B.R2
,A.CommentID
,A.ReplyCommentID
,A.Lvl
,CommentText = Replicate(@Nest,A.Lvl-1) + C.CommentText
-- Include any other fields from [dbo].[Blog_CommentDetails] alias C
From cteR1 A
Join cteR2 B on A.CommentID=B.CommentID
Join [dbo].[Blog_CommentDetails] C on A.CommentID=C.CommentID
Order By A.R1
返回
如果@Top设置为23（例如），则返回
我应该补充一点，cteR2不是必需的，但确实表明了范围和/或父级或叶级。
答案 1 :(得分：2)
您可以像下面显示的smippet一样订购它：
select coalesce(replycommentid, commentid) as sequence, ...
order by sequence, ...
父行将使用它自己的id作为序列。
答案 2 :(得分：2)
您应该使用递归CTE。这是改编from your later question
WITH CTE AS
(
SELECT CommentID, CommentUserName, CommentText,CommentDate,ReplyCommentID,
CommentID as ThreadID,
CAST(CommentID as varchar(MAX)) as PathStr
FROM Blog_CommentDetails as T
WHERE ReplyCommentID IS NULL
UNION ALL
SELECT T.CommentID, T.CommentUserName, t.CommentText,T.CommentDate,
T.ReplyCommentID,
CTE.ThreadID,
PathStr+'-'
+CAST(T.ReplyCommentID as varchar(MAX)) as PathStr
FROM Blog_CommentDetails as T
JOIN CTE ON T.ReplyCommentID = CTE.CommentID
WHERE T.ReplyCommentID IS NOT NULL
)
SELECT * FROM CTE ORDER BY ThreadID,PathStr,CommentID, CommentDate desc
结果：
╔═══════════╦═════════════════╦═══════════════════════╦═════════════════════════╦════════════════╦══════════╦═════════╗
║ CommentID ║ CommentUserName ║ CommentText ║ CommentDate ║ ReplyCommentID ║ ThreadID ║ PathStr ║
╠═══════════╬═════════════════╬═══════════════════════╬═════════════════════════╬════════════════╬══════════╬═════════╣
║ 22 ║ Vikash ║ This is main comment ║ 2016-11-12 17:36:25.637 ║ NULL ║ 22 ║ 22 ║
║ 23 ║ Megha k ║ This is reply comment ║ 2016-11-12 17:39:04.250 ║ NULL ║ 23 ║ 23 ║
║ 24 ║ Siddappa H ║ This is reply text. ║ 2016-11-12 17:39:58.847 ║ 23 ║ 23 ║ 23-23 ║
║ 26 ║ Vikash ║ This is reply text ║ 2016-11-12 17:41:44.673 ║ 23 ║ 23 ║ 23-23 ║
║ 25 ║ Suresh P ║ This is reply comment ║ 2016-11-12 17:40:44.470 ║ NULL ║ 25 ║ 25 ║
╚═══════════╩═════════════════╩═══════════════════════╩═════════════════════════╩════════════════╩══════════╩═════════╝
答案 3 :(得分：0)
如果我了解您正在寻找的内容，您希望在发表任何（非回复）评论之前，每个评论都会跟随其回复。我想你想要的只是这个：
#include<stdio.h>
int main() {
double f;
scanf("%lf",&f);
printf("%lf",f);
return 0;
}
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